The rules

The concept of function is input and output which also well known as X and Y. When you input a number into an equation,it produces an output (Y).Does it sound a little bit complicated? Then let's see an example about it!

We have an equation Y=X+1.We just learned that X is the input,so we can easily change it to any number we want to be the input. If X=1,then the equation becomes Y=1+1,therefore,y=2.We then know that when X=1,Y=2.We can use the same way to find the other outputs!

Now we have a table of values which helps us to evaluate and graph the function(Sometime it is not necessary)

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So far so good?Then let's learn some rules about the world of functions.

We always use f(x)= to represent a function. For example,f(x)=x+1.

It's really easy isnt it?Then let's learn some more exciting stuff.

We know that X is the input,Y is the output. In order to make the function more visual and direct ,we can turn it into a graph.

This is a graph

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Now,we will take a close look at the most basic function,linear function